This invention relates to an ultrasonic nebulizer driving circuit capable of stabilizing the driving power of an ultrasonic vibrator to maintain a constant nebulizing rate.
In an ultrasonic liquid nebulizer of conventional type, it is usual to drive a piezo-electric vibrator provided at the bottom of a vessel containing a liquid to be nebulized with a driving circuit so as to generate ultrasonic waves, and the energy thereof nebulizes the liquid, such as water. Generally, no output stabilization is provided, and variation of the input AC voltage (e.g. 48 V) causes a sharp variation of the nebulizing rate. Accordingly, a conventional circuit cannot be used for the atomization of kerosene in burners or the nebulization of medicine in medical apparatus, e.g., where a constant nebulizing rate is required.
Accordingly, an object of the present invention is to provide an ultrasonic wave nebulizer driving circuit capable of stabilizing the piezo-electric vibrator driving power to maintain a stabilized nebulizing rate. This object is obtained by utilizing negative feedback to stabilize oscillation, derived from sensing voltage or current or power supplied to the piezo-electric vibrator.
Explanation will be made hereinafter of presently preferred forms of ultrasonic wave nebulizer driving circuits embodying the present invention .